Woven slit films of polypropylene with deniers of between about 300-1500 in the warp and weft and with a tensile strength (ASTM D-1682 (Instron)) in pounds in the warp direction of at least 70 and in the weft or fill direction of at least 40 are useful as foundation coverings on the framework of wooden furniture in areas such as back, seat, and sides, etc. This foundation covering is not part of the visible upholstery.
Unfortunately, unmodified woven slit films of polypropylene when cold cut and/or stapled readily ravel. In order for such wovens to be useful they must have a dimensional stability of at least 3 pounds to satisfactorily overcome this tendency to ravel. Dimensional stability for purposes of this Specification and Claims is the force in pounds required to remove 10 ends from a 4 inch wide sample using a 1 inch wide bar containing five pins mounted in the lower jaw of an Instron. The direction as to warp or weft is the direction in which the force is applied.
One method for stabilizing woven polypropylene fabric is to apply an adhesive coating of some kind. However, most adhesive coatings will either lack sufficient adhesion, or introduce undesirable stiffness to the coated fabric, or introduce a tackiness and/or tendency to block to the degree that such fabrics are not useful as foundation coverings. In addition to these concerns relating to the properties of the finished fabric, ease of processing is also very important.